StepOne function

Penalized mediation and outcome models

An auxiliary function which conducts variable selection of X for Y using penAFT, X for M using the selected penalized model and M for Y using penAFT.

StepOne(X, M, time, status, model_option = "MCP")

Arguments

• X: An n by p matrix of exposures.
• M: An n by p matrix of mediators.
• time: A vector of survival time of samples.
• status: A vector of status indicator: 0=alive, 1=dead.
• model_option: The penalization method used when selecting X for M. The options include MCP, elastic net and lasso. Default is MCP.

Returns

A list with the following components: - X_sel_Y_s1: X selected for Y using penAFT

• M_X_s1: X selected for M using the selected penalized model

• M_sel_Y_s1: M selected for Y using penAFT

Examples

data(example_dat)
surv_dat <- example_dat$surv_dat
res_step1 <- StepOne(X = example_dat$X, M = example_dat$M, time = surv_dat$time,
status = surv_dat$status, model_option = "MCP")